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The E-3 Sentry, the best AWACS aircraft of the world from Boeing, is based on Boeing 707/320 commercial airframe. The builder is Boeing Aerospace Co. and the power plants are four Pratt and Whitney TF33-PW-100A turbofan engines, thrust 21,000 pounds each engine (9,534 kgs). With a rotating radar dome and kinds of eletronic mountings, the E-3 becomes the control and communication center of US military forces in theater of operations. Engineering of the E-3 began in October 1975. The testing prototype is a modified Boeing 707/320 renamed EC-137D. March 1977, the 552nd Airborne Warning and Control Wing received the first E-3. The last of 34 U.S. AWACS aircraft was delivered in June 1984. The radar dome on the back is the most special part of the E-3 to other aircrafts in appearance. It is 30 feet (9.1 meters) in diameter, six feet (1.8 meters) thick, and held 11 feet (3.3 meters) above the fuselage by two struts. It contains a radar subsystem that permits surveillance from the Earth's surface up into the stratosphere, over land or water. The detect range is more than 200 miles (320 kilometers) for low-flying targets and farther for medium to high altitudes. An identification friend or foe subsystem of the radar can look down to detect, identify and track enemy and friendly low-flying aircraft by eliminating ground clutter returns. In this situation, other types of radars may be confused. The unit cost of the E-3 is approximately $270 million, which is greatly effected by the high price eletronic equipment onboard.
The E-3 can gather and present broad and detailed battlefield information for different military units in real time, which includes position and tracking information on enemy aircraft and ships, and location and status of friendly aircraft and naval vessels. In time of crisis, such as Nuclear strike, this data can be forwarded to the National Command Authorities in the United States. As an aircraft, the Sentry has an excellent chance of surviving in war. The flight path can quickly be changed according to mission and survival requirements. The E-3 can fly a mission profile for more than 8 hours, or much longer through inflight refueling. The aircraft can be used as a surveillance asset in support of other government agencies during counter drug operations. U.S. Customs Service officers may fly aboard the E-3 Sentry on precoordinated missions to detect smuggling activities. There are four E-3 Sentries in Pacific Air Forces assigned to the 961st Airborne Air Control Squadron (AACS), based in Japan, and the 962nd AACS, Elmendorf AFB, Alaska. NATO E-3 with NATO commemoration painting
Saudi E-3
E-3 Sentry were among the first to deploy during Operation Desert Shield. During Desert Storm, E-3s flew more than 400 missions and logged more than 5,000 hours of on-station time. The E-3 controllers assisted in 38 of the 40 air-to-air kills recorded during the conflict. Experience has proven that the E-3 Sentry can respond quickly and effectively to a crisis and support worldwide military deployment operations. Improvement program for the E-3 began with a U.S. Air Force award of the ICON (Integration Contract) to Boeing in May 1987. ICON will equip both U.S. and NATO E-3s with an electronic support measures (ESM) passive surveillance capability, and other enhancements to the U.S. E-3 fleet. In 1989, the US airforce received the first 7 E-3s with the Boeing "Radar system improvement project RSIP" rebuilt. RSIP updates the pulse Doppler radar`s sensitivity and counter-countermeasures ability, as well as the GPS added on. And the radar operators console is updated, replaced the radars existing computer with a new high-reliability multiprocessor and rewrite the radar software to make it easier to maintain and enhance in the future. The Northrop Grumman offered the radar computer, radar control maintain interface and other hardware in this project. The whole project is completed after the NATO and UK E-3s got the same updates in 1996.
In October 1994, the USAF Air Combat Command (ACC) initiated Extend Sentry, a program to upgrade and extend the life of the E-3 AWACS fleet through the year 2025. Extend Sentry will help meet immediate Air Force sustainment needs. Extend Sentry will address issues such as obsolete parts, increased maintenance, repair downtime and a shrinking supplier base. Feb 2005, Boeing recently completed upgrading the first of four French E-3F AWACS aircraft with a Radar System Improvement Program (RSIP) kit, ahead of schedule. The modification is part of a $133 million foreign military sales contract with Hanscom, Air Force Base, Mass. "This is the most significant upgrade to the French AWACS fleet since its delivery in the early 1990s," said Nigel Lo, Boeing RSIP program manager. "It also will bring France's surveillance capability up to same standards as its NATO allies". The other three AWACS aircraft will receive upgrades by mid-2006 to improve the E-3F's surveillance capability by increasing the sensitivity of the pulse Doppler radar so the aircraft can detect and track smaller targets. It also improves the radar's electronic counter-countermeasures capability. Air France Industries, under subcontract to Boeing, performed the installation and checkout at its facility in Le Bourget, France. Boeing flight-tested the upgraded aircraft at the main operating base for the French AWACS in Avord, France. RSIP kits, built by Northrop Grumman Electronic Systems, upgrade the surveillance radar's existing computer with a new high-reliability multi-processor. New radar software is easier to maintain and enhance in the future. The modification also upgrades the radar's antenna, receivers and transmitters. A unit of The Boeing Company, Boeing Integrated Defense Systems is one of the world's largest space and defense businesses. Headquartered in St. Louis, Boeing Integrated Defense Systems is a $27 billion business. It provides network-centric system solutions to its global military, government, and commercial customers.
Length: 145 feet, 6 inches (44 meters) 机长： 44米 The bad time for E-3. 当然E-3风光一时也有倒霉的时候：
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The variations of E-3 include E-3A, E-3B, E-3C and E-3D. The A type is the first production version for US airforce. A type`s inside is quite different from the prototype, the modified fuselage can hold 17 people. They are 4 pilots, 12 operators and 1 onboard officer. The operators will charge the communication, computer, radar and 9 multi-function display plat. The equipment can be devided into six parts which are radar, IFF, data processing, communication, navigation, data display and control. The radar system includes the Northrop Grumman AN/APY-1 radar, the multi function of the radar can seperate the whole 360 degree area into 32 parts and use different function in each part. Scan once, the IFF system can check over 200 targets with IFF receiver installed, no matter the target is in the air, on the ground or sea.
There are some other major subsystems in the E-3, navigation, communications and computers (data processing). The navigation subsystem can offer a total positioning deflection less than 3.7km. The data display and control system is mainly formed of data display, multi-function control plat, eletronic typewriter and assis-display. The data can be showed in original size or zoom to 32 times bigger, the latter is for detect and control fighters to proceed dog-fight mission. The data processing system can record, save and operate the data from the radar, IFF, navigation and other equipment in the aircraft. The system can process 400 targets or 600 for european variations. The operators onboard will look at the consoles display computer-processed data in graphic and tabular format on video screens to check all the information. And the operators will perform surveillance, identification, weapons control, battle management and communications functions.
The E-3B is developed from the first two E-3s, the target processing and ship detecting ability is strengthened. The E-3C and E-3D is designed for NATO and UK which is close to B type. NATO airforces have acquired 18 of the aircraft and support equipment for US$ 2 billion. The first E-3 was delivered to NATO in January 1982. The Peace Sentinel program for Saudi Arabia began in 1981. It included five AWACS aircraft and six E-3 derivative (KE-3) inflight refueling tanker aircraft, along with spare parts, trainers and support equipment. In 1984, the Saudi government exercised an option to increase the tanker order to eight. The United Kingdom ordered six E-3s in 1987 after some frustrations, US$ 260 million each, later order for one more E-3 added on. And France ordered 3(photo up here) for US$ 330 million each, deployed between 1989 to 1992, as well as one added on, too.
